Analysis: The only player who ramped up his production was Emmanuel Sanders, who doubled his catches from a season ago (22 to 44) but also was on the field nearly twice as much as in 2011. Mike Wallace played more than any receiver (852 snaps), but his numbers were down across the board from 2011. While his holdout might not have affected his production, it set a non-positive tone for the season. Antonio Brown, given a $42.5 million contract in training camp despite having only two career touchdown catches, made five TD receptions but didn‘t replicate his 2011 Pro Bowl season. Even with the change in offensive coordinators from Bruce Arians to Todd Haley and his controlled passing offense, it wasn‘t what the Steelers wanted and needed from a position of perceived strength.

The position the Steelers were least worried about heading into the 2012 season might be the one that concerns them most going in 2013.

Even as big-play wide receiver Mike Wallace held out during training camp, Antonio Brown signed a $42.5 million contract and Emmanuel Sanders looked like a starter in waiting. Possession receiver Jerricho Cotchery added depth and a valuable third-down option.

All Ben Roethlisberger and Todd Haley needed to do was decide how to spread out all the receptions and all the yardage.

“(Early in the season) we had everything we wanted,” Cotchery said. “We were moving the ball so well. We were growing.”

Fumbles, close losses, injuries and the lack of a running game conspired to ruin all that September optimism.

Wallace didn‘t play like a receiver in a contract year — it didn‘t help that the deep ball was ignored game after game — and Roethlisberger‘s three-game midseason injury layoff proved to be the undoing of a season.

“There‘s a lot of stuff that‘s going to come from this,” Brown said of the Steelers‘ 8-8 season. “A lot of learning.”

And a good bit of rebuilding.

Wallace seems likely to leave via free agency in two months, creating a major void in an offense that must replace the 235 passes he caught and 32 touchdowns he produced over the past four seasons. And, likely, an expensive void to fill.

Despite Wallace‘s downslide this season — he graded out among the NFL‘s top 15 receivers in 2011 but in the bottom 15 this season, based on Pro Football Focus‘ play-by-play analytical breakdown — it might not be easy to replace what arguably was the fastest wide receiver in Steelers history.

“I think one of the things that probably hurt them was that Wallace was one of those guys who didn‘t understand that this is a business,” said former Cowboys personnel chief Gil Brandt, now a SiriusXM NFL Radio analyst. “They paid him for what he did this year, and he kind of played mad at the team and organization.”

The Steelers ended up paying Brown approximately the amount of money they intended to pay Wallace, but he didn‘t exactly play like a No. 1 receiver, either. Brown‘s own three-game injury absence (high-ankle sprain) set him back as he failed to duplicate his team MVP season of 2011, when he was a 1,000-yard receiver and kick returner.

Brown caught nearly as many passes (66) as he did the season before (69), but his yardage dropped from 1,108 to 787 and his punt return average declined from 10.8 yards to 6.8. He also badly hurt the Steelers with second-half fumbles that ended up being the pivotal plays during road losses to the Raiders and Cowboys.

Brown is known to work relentlessly on his conditioning, but he realizes other aspects of his game need polishing before next season, when he might be the team‘s unquestioned No. 1 receiver.

“A point of emphasis for me will be protecting the ball better, becoming a better route receiver and a better return man,” Brown said.

Even if the Steelers decide Sanders can replace Wallace as a starter — Sanders had only two games of 60 yards receiving or more — they must find someone to replace a No. 3/slot receiver who was on the field for 740 snaps.

There might not be an affordable replacement on the free-agent market, which means a suddenly thin position depth-wise might have been to addressed multiple times in the draft — and in a year when the Steelers have numerous pressing needs.

“Wide receiver becomes an issue for them,” said former NFL general manager Charley Casserly, now an NFL Network analyst.